Conventional packet-switching networks permit cheap and reliable communications independent of the distance between a source node and a destination node in the network. These conventional networks often rely upon either public keys or shared private keys to provide privacy for messages that pass through the network's links. Public key cryptographic systems have the drawback that they have never been proven to be difficult to decipher. Therefore, it is possible that a method of efficiently cracking public key systems may one day be discovered. Such a discovery could make all public key technology obsolete. All supposedly “secure” networks based on public key technology would thus become vulnerable. Shared private keys also have the drawback that the logistics of distributing the private keys can be prohibitive.
Quantum cryptography represents a recent technological development that provides for the assured privacy of a communications link. Quantum cryptography is founded upon the laws of quantum physics and permits the detection of eavesdropping across a link. Quantum cryptographic techniques have been conventionally applied to distribute keys from a single photon source to a single photon detector, either through fiber optic strands or through the air. Although this approach is perfectly feasible for scientific experiments, it does not provide the kind of “anyone to anyone” connectivity that is provided by current communications technology. Conventional quantum cryptographic techniques require a direct connection to anyone with whom one wishes to exchange keying material. Obviously, a large system built along these lines would be impractical, since it would require every person to have enough sources and/or detectors, and fiber strands so that they could employ a dedicated set of equipment for each party with whom they intend to communicate.
Furthermore, conventional quantum cryptographic techniques fail to adequately handle the situations in which eavesdropping is present on a link or when a dedicated link fails (e.g., a fiber is accidentally cut). In conventional quantum cryptographic techniques, further key distribution across the dedicated link becomes impossible until eavesdropping on the link ceases or the link is repaired.
It would, thus, be desirable to implement a quantum cryptographic network that could provide the “any to any” connectivity of conventional packet-switching networks, such as the Internet, while eliminating the need for a direct connection between parties distributing quantum key material, and which may further sustain key distribution even with link failure and/or when eavesdropping exists on the link. Conventional packet-switching networks have employed numerous different types of network management protocols and systems for configuring and managing the nodes of the networks. In a quantum cryptographic network that provides “any to any” connectivity, network management protocols and systems may be employed to assist in building and maintaining a multi-node, multi-link quantum cryptographic network. A quantum cryptographic network with network management functionality may be more easily configured, monitored and actively managed.
Therefore, there exists a need for systems and methods that can provide network management functionality for configuring, monitoring and managing links and nodes of quantum cryptographic networks.